Your Applet wouldn't load on my system. All I got was a grayish-blue blank screen. My OS is Windows 7 (64 bit) and my Java is up to date. I would recommend that you try breaking your applet down to its simplest parts. Once you have that working, add back in your other stuff until it breaks. That will tell you where the problem is.

That shouldn't cause any problems while its running, but likely means your code is not very maintainable. You should look into component based entities, which is a popular design pattern to eliminate the need for deep object hierarchies.

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